Multiplying Decimals

Multiplying by Powers of 10

100

What is 3.6 x 10³?

3,600

200

What is 2.2 x 10⁵?

220,000

300

Milo walked 1.8 x 10⁴ steps yesterday. How many steps did Milo walk yesterday?

18,000

400

What is 4.32 x 10²?

432

500

Which of the following are equal to 8.3 x 10⁵? Choose all that apply. 

A) 8.3 x 10 x 5

B) 8.3 x 10 x 10 x 10 x 10 x 10

C) 830,000

D) 83,000

B & C

Estimating

100

What is a good estimate for 3.6 x 5.7?

Your answer should be similar to:

4x6=24

OR 

Between 3x5=18 and 4x6=24

200

What is a good estimate for 12.34 x 4.5?

Your answer should be similar to:

12x5=60

OR 

Between 12x4=48 and 13x5=65

300

A rectangular card measures 7.8 inches long and 4.3 wide. What would be the best estimate for the area of the card?

Your answer should be similar to:

8x4=32

OR

Between 7x4=28 and 8x5=40

400

Colton goes to the store to buy bags of chocolate chips. Each bag costs $2.74. He needs 6 bags for the 6 batches of chocolate chip cookies he wants to make. About how much will it cost to buy 6 bags of chocolate chips?

Your answer should be something similar to:

3x6=18

OR 

Between 2x6=12 and 3x6=18

500

Jocelyn solves 3.8 x 4.1 and gets an answer of 155.8. Is this a good estimate? Why or why not?

Example answer:

No because I estimated 4x4=16 and that is a lot smaller than 155.8

Multiplying by a Whole Number

100

What is 5 x 0.8?

4

200

What is 12 x 0.7?

8.4

300

What is 17 x 0.8?

13.6

400

What is 28 x 7.3?

204.4

500

What is 43 x 0.61?

26.23

Multiplying by two decimals

100

What is 0.3 x 0.6?

0.18

200

What is 0.1 x 0.8?

0.08

300

What is 4.5 x 0.9?

4.05

400

What is 7.1 x 3.6?

25.56

500

Which sum is equivalent to 5.3 x 0.8?

A) 380 + 44

B) 38 + 4.4

C) 3.8 + 4.4

D) 3.8 + 0.44

D

Place Value

100

If 4x7=28, what is 0.4 x 7?

2.8

200

If 12 x 12 = 144, what is 1.2 x 1.2?

1.44

300

If 63 x 47 = 2,961 , what is 63 x 0.47?

29.61

400

If 6.3 x 47 = 296.1, what is 63 x 4.7?

296.1

500

If 5.8 x 5.5 = 31.9, what is 5.8 x 55?

319